The objective of the Guidance Document is to provide guidance on how to interpret the outcome of individual tests and how to increase evidence on whether or not a substance may be an endocrine disrupter. However, testing strategies or guidance on interpretation from a suite of tests are not given.

- to provide guidance on how test results might be interpreted in the light of data that may already be available from other in vitro or in vivo assays. The key questions addressed concern likely mechanisms of endocrine action and any resulting apical effects that can be attributed to such action.

- to provide advice on the next step in testing (if any) which might be appropriate for a regulatory authority to take, given the various data scenarios.

This guidance document was developed as a follow-up to the workshop on OECD countries’ activities regarding testing, assessment and management of endocrine disrupters, which was held in Copenhagen (Denmark) on 22-24 September 2010 (see document No. 118 published in the Series on Testing and Assessment). The guidance document was developed by two consultants in close cooperation with an advisory group on testing and assessment of endocrine disrupters (EDTA AG). The guidance document was approved by the Working Group of the National Coordinators of the Test Guidelines Programme, representing regulatory authorities. It is published in the OECD Series on Testing and Assessment, which is a collection of guidance documents, review papers, analytical reports and workshop reports on chemical testing and non-testing methods and hazard assessment. These publications are part of the OECD work on chemical safety.